Unison said it has been given permission by the High Court to seek a judicial review over employment tribunal fees put in place today.
The introduction of punitive fees for taking a claim to an employment tribunal would give the green light to unscrupulous employers to ride roughshod over already basic workers' rights.
The Government should not put a price on justice.
Unison's judicial hearing will be held in October.
More top news
Since Friday's EU result, the Liberal Democrats have recorded thousands of voters signing up to become members.
Anthony Joshua vowed to rest after retaining his heavyweight title.
Adele described performing at Glastonbury as the "best moment" of her life as she took to the Pyramid Stage.